Scintillation materials of low oxygen content and process for producing same

Abstract

The scintillation material has a maximum oxygen content of 2,500 ppm and is a compound of formula LnX 3 or LnX 3 :D, wherein Ln is at least one rare earth element, X is F, Cl, Br, or I; and D is at least one cationic dopant of one or more of the elements Y, Zr, Pd, Hf and Bi and, if present, is present in an amount of 10 ppm to 10,000 ppm. The process of making the scintillation material includes optionally mixing the compound of the formula LnX 3 with the at least one cationic dopant, heating the compound or the mixture so obtained to a melting temperature to form a melt, adding one or more carbon halides and then cooling the melt to form a crystal or crystalline structure. The maximum oxygen content of the scintillation material is preferably 1000 ppm.

We claim: 
     
       1. A scintillation material with a maximum oxygen content of 2,500 ppm and comprising a compound of general empirical formula LnX 3 :D, wherein Ln is at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; X is Cl, Br, or I; and D is at least one cationic dopant comprising of one or more of Zr, Hf, Pd, and Bi and is present in an amount of 10 ppm to 10,000 ppm;
 wherein said scintillation material is made by a process comprising the steps of:
 a) optionally mixing a compound of the general empirical formula LnX 3  with the at least one cationic dopant to form a compound having the general empirical formula LnX 3 :D, or otherwise providing a compound of the general empirical formula LnX 3 :D; 
 b) heating the compound of the general empirical formula LnX 3 :D to a melting temperature thereof to form a melt; 
 c) adding at least one carbon-containing compound to the compound or to an atmosphere above the melt; and 
 d) cooling the melt to obtain a single crystal or a polycrystalline structure. 
 
 
     
     
       2. The scintillation material according to  claim 1 , wherein the maximum oxygen content is 1,000 ppm.